Antiknock motor fuel



Patented Mar. 18, 1941 UNITED TATE PATENT OFFICE ANTIKNOCK MOTOR FUEL NoDrawing. Application June c, 1938, Serial No.

212,128. In the Netherlands June 15, 1937 a 1 Claim.

This invention relates to gasoline type motor fuels, 1. e., motor fuelssuitable for use in gasoline engines, and more particularly deals withgasoline type motor fuels of high antiknock properties containing metalorganic knock suppressors.

As is well known, certain mlneral oil-soluble metal organic compounds,such as tetraethyl lead, nickel and iron carbonyls, ethyl selenide,etc., have the property of suppressing detonation or knock inspark-ignition engines. These compounds are generally known as antiknockcompounds. While some of them are highly effective, they are all subjectto at least one or sev-' eral serious disadvantages, such as extremelyinsufliclent solubility in hydrocarbons, high toxicity, poor storagestability, corrosiveness to the engine, etc.

It is a purpose of this invention to provide a class of efllcient knocksuppressors comprising metal organic compounds which are substantiallyfree from the above disadvantages or at least possess them to a verymuch smaller extent, It is another purpose to provide non-toxicantiknock compounds readily soluble in gasoline having efllcienciscomparable to those of tetraethyl lead; and it is a further purpose toproduce antiknock gasolines containing metal organic antiknock compoundswhich upon storage for several months do not substantially decompose anddepreciate in antiknock value.

We have discovered that metal organic compounds belonging to a class ofcompounds similar to those described in U. S. Patent No. 2,023,372

0 but differing from the latter by greater solubility in gasoline andgreater antiknock value, may have knock-suppressing properties equal toor even better than the most potent known antiknock compounds. Ourknock-suppressors are non-toxic, reasonably stable in storage, andgasolines containing small amounts thereof, i. e., equal in antiknockvalue to about 3 cm; tetraethyl lead per gallon of gasoline, do notcorrode valves and valve seats, nor do they cause undue wear of movingengine parts.

Our knock-suppressors are compounds of a metal having an atomic numberof 26 to 29 inclusive, i. e., a metal selected from the class consistingof iron, nickel, cobalt and copper, and an organic substance containingboth nitrogen and oxygen based on the following structural formula orits equivalent:

HOC=CC=NR| R1 and R1 are hydrogen or organic radicals and R3 is anorganic radical selected from the group consisting of alkyl, aryl andaralkyl, which may or may not contain one substituent. The radicals R1,R2 and R3 should preferably not contain more than 6 carbon atoms intotal. Moreover, R2 jointly with R1 may form a ring structure, if thejoined radicals contain a suificient number of carbon atoms to form atleast a 4-carbon ring. Suitable substituents in hydrocarbon radicals R1to R3 are all those which are capable of forming substantially stablecompounds with hydrocarbons, such as halogen, CN, OH, OH,, COR, NHz,NHR, NR2, --SH, SR, COOR, etc., neutral and basic substituents beingpreferred to those which are strongly acidic, such as COOH, SOsH, etc.

As is well known, in compounds of the above formula the double bonds arecapable of shifting their exact location within the molecule dependingupon the surrounding conditions, thereby forming the enol or keto formsand amino or imino forms, respectively. Therefore the followingstructures are considered full equivalents of the above:

i. at

The metal compounds of our invention may be conceived as salts orcomplex compounds or both. It is believed that the metal is usuallyattached to the oxygen as follows:

where Me is a metal having an atomic number of 26 to 29, and n is thevalence of the metal. It is, however, likely that in addition there arelinks of secondary valences between the metal and the nitrogen, givingthe compounds the character of complex compounds.

Our knock suppressors may be prepared by reacting for instanceoxymethylene acetaldehyde or oxymethylene acetone or homologues thereof,either in the free state or in the form of their alkali metal salts ortheir compounds with alcohols, such as ethers and acetals, with primaryorganic amines, such as mono alkyl amines, mono alkanol amines, alkylenediamines, aniline, chlor aniline, etc. When starting from alkali metalsalts of the oxymethylene compounds, the amines should be applied in theform of their salts, e. g., the hydrochlorides, whilst when startingfrom acetals of the oxymethylene compounds it is preferable to carry outthe reaction in the presence of water. The resulting reaction productsare purified by suitable methods and are then converted to the desiredmetal compound for instance by treating same with copper acetate whilelnsolution of a suitable solvent, such as an alcohol having not more than4 carbon atoms.

The anti-knock value of our compounds depends to some extent on theirvolatility and solubility in gasoline. In the absence of polar radicais,solubility increases and volatility decreases in general with increasingmolecular weight of the organic component. If both R; and R: arehydrogen the solubility in gasoline of the metal compound may be quitelow, but suflicient, so that the corresponding compounds of copper andthe ferrous metals are useful as antiknoek compounds. If R1 or Rs orboth are organic radicals, metal compounds thereof may be miscible withgasoline in substantially all proportions. On the other hand, if themolecular weight of the organic compound exceeds about 300 then thevolatility becomes low and under average carbureting conditions aportion of the metal compound may deposit in engine manifolds instead ofbeing drawn into the combustion chambers of the engines.

Compounds which are sufficiently volatile to reach the combustionchamber of gasoline engines under average carburetion conditions withoutmaterial deposition in the manifold are usually distillable withoutsubstantial decomposition under high vacuum 1. e., a vacuum of about 0.1mm. mercury or lower.

Some of our metallic organic compounds are normally liquid while othersare normally solid. Certain of those which possess highest antiknockvalues, such as the copper compound of methyl amino methylene acetone,are normally solid. However, it appears that the normally solidcompounds have certain disadvantages as against those which are normallyliquid. For instance, the former have a greater tendency of formingdeposits in engine manifolds under average carburetion conditions andalso in general are less soluble in gasoline. We have found, thatfrequently mixtures may be normally liquid, which mixtures consistessentially of our normally solid and normally liquid compounds and maycontain the normally solid components in substantial proportions. Suchliquid mixtures are highly useful as they may combine all the advantagesof the normally liquid compounds with the very high antiknock value ofthe normally solid compounds.

Solubilities of little soluble compounds may also be improved by theaddition of mutual solvents, such as the lower alcohols, ketones,ethers. amines, etc., boiling preferably within gasoline boiling range.

If desired gasoline type motor fuels may be prepared consisting entirelyor predominantly of neutral oxyhydrocarbons, such as ethers, ketones, oralcohols, particularly those with branched carbon chains and boilingwithin gasoline boiling range, containing small amounts of our antlknockcompounds.

The amounts of our antiknock compounds nor. mally incorporated into thefuels to effect an improvement in the knock rating may vary from a baretrace to about .5% metal by weight of the fuel, although larger amountsmay be used, if degin-on ems-0 si-crn u (or C0) N-CH:

on- B Other suitable compounds are: the cupric or cobalt compound ofallyl amino methylene pinacoline having the formula:

the cupric or cobalt compound of ethyl amino methylene acetaldehyde.

u(or Col Further examples of suitable compounds are the copper, iron,nickel or cobalt compounds of the following organic componnets:

CHr-C O-CH=CHNEC1H; (Ethyl aminomethylene acetone) CHr-C OCH=CH-NHC:H(Allyl aminomethylene acetone) CrHs CHr-C O-O=CHNHCH; (Methylamlnomethylene peutanone-Z) C(CHr):

CHx-C 0- =CB-NHCzHs (Allyl aminomethylene methyl neopentyl ketone)CoHr-C OCH=CH-NHC:H; (Allyl aminomethylene acetopbenonc) CHsC- 0HELCH=CHNHCH: (Methyl aminomethylone acetaldehyde) 0 on 11 -c=cn-Nrtcin(Methylaminomethyleue propionaldehyde) Also mixed compounds of copper orthe ferrous metals with different species of the organic componentshereinbefore described, or with other compounds, such as alcohols,phenols, mercaptans may be employed For instance the basic alcoholate ofthe cuprlc compound of methyl amino methylene pinacoline was found -tobe an active antiknock compound. It may be represented by the formula:

Furthermore mixtures of two or more of our anti-knock compounds, as wellas mixtures with other anti-knock compounds, such as tetraethyl lead.may often be used to great advantage.

The following illustrative examples further demonstrate our invention:

Example I To two samples of a gasoline, having an octane number or 40,the copper compound of methyl aminomethylene acetone was added inquantities, so that the blended gasoline contained .05% and .1respectively copper by weight of the gasoline. As a result'the octanenumbers were raised [to 59 and 69 respectively.

The same gasoline was blended with tetraethyl lead in quantities toproduce two blends containing .05% and .l% lead .by weight or thegasoline.

The resulting octane numbers were 55 and 66 respectively.

' Example II To the gasoline of Example I .05% by weight of copper wasadded in the form of the copper compound of methyl aminomethylene2-pentanone. The octane number rose to 58.

Example III .1% copper in the form of the copper compound oi ethylaminomethylene acetone was added to the gasoline of Example I, therebyraising its octane number to 6'7.

Example IV .l% by weight of copper in the form of the cupric compound.ofallyl aminomethylene acetone raiscdthe octane number of a gasoline fromExample V To a gasoline. the octane number of which was 40, .04% byweight 01' cobalt was added in the form of the cobaltous compound ofethyl aminomethylene acetone. The octane number rose to 64.

Example VI raised the octane number 01' a gasoline from 40 Example VIII.10% copper in the form of cupric ethyl aminomethylene acetaldehyde(HO-CH=OHNHCQHC) raisedthe octane number 01 a gasoline from 40 to 64.5.

Example IX .03% copper in the form of a normally liquid mixtureconsisting of 30 parts by weight solid cupric methyl aminomethyleneacetone and 70 parts oi. liquid cupric ethyl aminomethylene acetoneraised the octane number of a strongly aromatic gasoline from '78 to 86.

Example X .l% copper in the form of cupric ethyl aminomethylene acetonein a mixture of 20% of this compound and 80% aniline raised theantiknock value of a gasoline from 40 to 71.

Example XI .1% cobalt in the form of the cobaltous compound of ethylaminomethylene acetone raised the octane number oi. a hydrogenationgasoline (prepared from Venezuelan gasoil) from 79 to 9'7.

Example XII .1% nickel in the form of the nickel compound of ethylaminomethylene pinacoline raised the octane number of a gasoline from 40to 60.5.

Example XIII .1% cobalt in the form of the cobaltomethylate of ethylaminomethylene acetone CH:(|J=CH-CII=NC:H

when added to a gasoline with an octane number of 40 raised this numberto 61.

Example XIV .1% copper in the form of the cupric compound of betaethoxyethylamino methylene acetone raised the octane number of agasoline from 40 to 61.

Example XV .05% cobalt in the form of the cobaltous compound of ethylaminomethylene acct/aldehyde ratzed the octane number of a gasoline from40 to 0.

We claim as our invention:

An improved motor fuel, which comprises a gasoline type motor ruel and asmall amount or a normally liquid mixture consisting of the normallysolid cupric methyl amino methylene acetone and o! the normally liquidcupric ethyl amino methylene acetone.

ADRIANUS JOHANNES VAR PESKI. NICOLAASMAX.

JOHANNEB ANDREAS VAR MEL-SEN. PIETER LUCAS STEDEHOUDER.

